CVE Watchtower

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CVE-2026-20957NVD

Vulnerability Summary

Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.
Severity Level
HIGH(7.8)
Published Date
Jan 13, 2026
Last Modified
Jan 14, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
Data Pending
Root Weakness (CWE)
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CVSS v3.1 Base Metrics — Score 7.8 (HIGH)
Attack VectorLocal
Attack ComplexityLow
Privileges RequiredNone
User InteractionRequired
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • Microsoft 365 Apps
  • Microsoft Excel
  • Microsoft Office
  • Microsoft Office Long Term Servicing Channel
  • Microsoft Office Online Server < 16.0.10417.20083
Patched Versions
  • Microsoft Office Online Server 16.0.10417.20083
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🎁7-Day Free Trial — Try Pro or Team, no card required.
📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
📈EPSS Spike Alerts — Catch rising risk before it peaks.
🎯Custom EPSS/CVSS — Filter noise, focus on risk.
🛡️Exploit Intel — A 2nd confirmed-exploit signal beyond KEV.
🐙GitHub Issues — Auto-tracked, no duplicates.
📬Weekly Digest — One clean summary, not inbox spam.
🏷️Watchlist Groups — Tag alerts by team (Infra/AppSec/SOC).
💬Webhooks — Slack & Teams integration.
🔀Smart Routing — Critical alerts to one channel, rest to another.
🚫Ad-Free — Uninterrupted experience.